Grinding machines



July 1, 1969 K. T. LAMBERT ETAL GRINDING MACHINES Sheet Filed Nov. 22,1966 July 1, 1969 K. T. LAMBERT ETAL GRINDING MACHINES Filed Nov. 22,1966 Shaer. ,8 of 2 FIG. 2-

United States Patent U.S. Cl. 51-55 10 Claims ABSTRACT OF THE DISCLOSUREA machine for grinding flat the ends of glass tubes includes arotatably-driven grinding wheel having a flat grinding face disposed ina plane perpendicular to the axis of rotation. During operation thegrinding wheel swings pendulum-fashion in said plane.

This invention relates to grinding machines and is in particular,although not exclusively, concerned with machines for grinding the endsof elongated articles such as glass tubes.

According to the present invention there is provided a grinding machinecomprising a grinding member supported for swinging with its grindingface disposed in an upright plane, means for imparting swinging motionto the grinding member, and means for supporting a Workpiece such that asurface of the workpiece can be moved into said plane to be ground bythe grinding member during said swinging motion thereof.

For a better understanding of the invention and to show how the same maybe carried into effect reference will now be made, by way of example, tothe accompanying drawings, in which:

FIGURE 1 is a diagrammatic side view of the grinding machine,

FIGURE 2 is a diagrammatic end view of the machine of FIGURE I viewed inthe direction of arrow II of FIG- URE 1, and

FIGURE 3 is a diagrammatic end view, on a larger scale, of a part of themachine of FIGURES 1 and 2 viewed in the same direction as FIGURE 2 andillustrating operation of the machine.

The machine is shown in FIGURES 1 and 2 set-up for; grinding the ends ofa glass tube 1 flat and parallel with one another. The machine has anelongated horizontal bed 2 on a flat slideway 2A of which are adjustablymounted for movement along the slideway two work rests 3 each carrying apair of rollers 4 for supporting a workpiece (in the case illustratedthe glass tube 1). The rollers 4 are of a synthetic plastic materialsuch as nylon.

At one end of the machine, the machine bed 1 carries an upright bracket'5 to the top of which is secured a motor 6. Adjacent the bracket 5 theend portion of the machine bed 1 carries two spaced apart yoke-likebrackets 7 which rigidly support, above the bed 1, a shaft -8 extendinglongitudinally and centrally of the bed 1 and coaxially with the shaftof the motor 6. A swinging arm 9 depends from the shaft 8 between thebrackets 7, bearings 10 housed in the upper portion of the arm 9co-operating with the shaft 8. Further bearings 11 housed in the bottomportion of the swinging arm 9 rotatably support a shaft 12 so that itextends longitudinally of the bed 1 and centrally thereof when the arm 9is hanging normally.

Each end of the shaft 12 projects from the arm 9 and the projecting endremote from the motor support bracket 5 carries a grinding wheel 13. Thewheel 13 is supported with its grinding face 13A perpendicular to theplane of the upper surface of the slideway 2A. The wheel 13 may be, forexample, a silicone carbide bonded wheel, or it may be a cast ironwheel. In a case such as the former pipes (not shown) for continuouslysupplying water to the wheel 13, during grinding, are provided whilst ina case such as the latter a continuous feed of silicone carbide slurryis fed to the wheel 13 during operation.

The projecting end of the shaft 12 that is adjacent the motor supportbracket 5 passes through bearings carried by a support bracket 14secured to the arm 9 and a pulley or sprocket wheel 15 is mounted onthis end of the shaft 12. The pulley or sprocket wheel 15 is below asimilar pulley or sprocket wheel 16 on the shaft of the motor 6 and anendless V-belt or chain 17 runs around the two pulleys or wheels 15, 16so that the motor 6 may drive the shaft 12 and therefore the grindingwheel 13.

A bracket 18 (FIGURE 2) extending horizontally from one side of themachine bed 1 carries trunnions 19, at its end remote from the bed 1,that pivotally support one end of an air cylinder 20. The rod 21 of apiston in this air cylinder 20 is pivotally connected to a lug 22 on thearm 9. The axis of the air cylinder 20 is transverse to the longitudinalaxis of the machine bed 1. A suitable pneumatic circuit (not shown) isprovided for causing the piston in the cylinder 20 to reciprocatewhereby swinging motion is imparted to the arm 9. The stroke of thepiston can be selected in accordance with the length of the are it isdesired the arm 9 should swing through. It will be appreciated that thedisposition of the shafts 8 and 12 is such that the grinding face 13A ofthe wheel 13 swings in a plane that is at right-angle to the plane ofthe upper sur face of the slideway 2A.

The operation of the grinding machine shown in the figures will now bedescribed with reference to the grinding of the ends of an elongatedworkpiece such as the glass tube 1 shown in the figures. To set-up themachine the work rests 3 are positioned on the bed 1 so that one set ofthe rollers 4 is about 3 inches from the grinding wheel 13 whilst theother set of rollers 4 support the tube 1 at about 3 inches from its endremote from the wheel 13, the work rests 3 being set so that the axes ofthe rollers 4 lie in the same horizontal plane. The stroke of the pistonin the air cylinder 20 is set to cause the swinging motion imparted tothe arm 9 to be such that throughout most of its movement the wheel 13entirely covers the end of the tube 1 when the tube is resting on therollers 4 with this end against the Wheel 13, but such that at the endof this movement in one direction a part of the end of the tube 1 isclear of the wheel 13. In this connection, it will be noted from thefigures that the disposition of the work rests 3 and the rollers 4 issuch that the tube 1 is supported offset from, but parallel with, thelongitudinal axis of the machine bed, the longitudinal axis of the tube1 extending normally to the plane in which the face 13A swings. Thus theworkpiece is supported so as to be displaced from the central point ofthe are through which the grinding wheel swings durin operation of themachine.

With the machine set-up as described, the motor 6 and the piston in thecylinder 20 are set in operation respectively to rotate the grindingwheel 13 and to cause the arm 9 to swing, and the tube 1 is placed onthe rollers and pushed, by hand, into contact with the rotating,swinging, grinding wheel 13. Feeding of the tube 1 to the grinding wheel13 is continued manually and, at the same time, the tube is manuallyrotated on the rollers 4. When grinding of one end of the tube has beencompleted, the tube is turned around and the other end ground in thesame way. It will be appreciated that, due to the construction of themachine, this end will be ground parallel to the end first ground. Inactual practice it has been possible to obtain parallelism of the twoends of a glass 3 tube such as the tube 1 to within .004 inch, the endsbeing ground to a flatness of within .002 inch.

If a somewhat misshapen, or even square, tube has to be ground, roundclamps are secured to the tube to rest on the rollers 4. The fixing ofsuch clamps to the tube enables the tube to be rotated on the rollers 4without the outside configuration of the tube affecting this rollingoperation.

It will be appreciated that, although manual feeding of an elongatedcircular glass tube resting freely on the work rests has been described,the machine can be provided with jigs and/or a mechanical feedarrangement to enable the ends of more intricately shaped articles to beground, for example, T-pieces, cross-pieces and tubes of hexagonal andoctagonal section. Also the machine is not, of course, restricted to thegrinding of glass articles.

We claim:

1. A grinding machine comprising a grinding member, a planar grindingface on the grinding member, means supporting the grinding member forswinging with its grinding face continually disposed in an uprightplane,

means for imparting swinging motion to the grinding member, and meansfor supporting a workpiece such that a surface of the workpiece can bemoved into said plane to be ground by the grinding face of the grindingmember during said swinging motion thereof.

2. A grinding machine according to claim 1, wherein the means supportingthe grinding member is a swingable arm, and wherein the grinding memberis a grinding wheel that is rotatably supported in said swingable arm,the machine further comprising means for rotating the wheel during saidswinging motion thereof.

3. A grinding machine according to claim 2, wherein the last-mentionedmeans includes a motor and an endless transmissionmeans for transmittingdrive from the motor to the grinding wheel.

4. A grinding machine according to claim 2, wherein the means forimparting swinging motion to the grinding member comprises atrunnion-mounted piston and cylinder arrangement pivotally connected tosaid arm.

5. A grinding machine according to claim 4, wherein the operationalstroke of the piston and cylinder arrangement is adjustable.

6. A grinding machine according to claim 1, wherein the workpiecesupporting means includes an elongated horizontal slideway andwork-rests adjustably mounted on the slideway for supporting anelongated workpiece such that its longitudinal axis extends normal tosaid plane.

7. A grinding machine according to claim 6, wherein said work-rests aremounted on the slideway so as to support an elongated workpiecedisplaced from the central point of the are through which the grindingmember swings during operation of the machine.

8. A grinding machine for grinding a surface of a workpiece to produce afiat surface comprising a rotatably driven grinding wheel having a flatgrinding face disposed in a plane which is perpendicular to the axis ofrotation of said grinding wheel; means supporting said grinding wheelfor arcuate swinging movement such that said grinding face swings insaid plane; means for imparting reciprocating swinging movement to saidgrinding wheel during rotation thereof; and means for supporting aworkpiece and for moving the same into but not through said plane andinto grinding engagement with said rotating and swinging grinding face.

9. A grinding machine as in claim 8 wherein said workpiece support meansis disposed to move the workpiece into said plane near one end of thearcuate path of travel of said grinding wheel whereby part of theworkpiece surface being ground may be clear of said grinding face atsaid end of the arcuate path of travel of said grinding wheel.

10. A method for grinding the end of an elongated workpiece to produce aflat surface comprising: rotating about its own axis a grinding wheelhaving a fiat grinding face disposed in a plane perpendicular to theaxis of rotation; moving said workpiece so as to engage said end withsaid rotating grinding face; and swinging said grinding wheel in saidplane while said end of said workpiece is in engagement with saidgrinding face.

References Cited JAMES L. JONES, JR., Primary Examiner.

US. Cl. X.R. 51-99, 125, 289

